SPRACL7 March   2019 AM5746 , AM5748 , AM5749

 

  1.   AM574x thermal considerations
    1.     Trademarks
    2. 1 Overview
    3. 2 Important Notes
    4. 3 Test Overview
      1. 3.1 OS Idle
      2. 3.2 Dhrystone
      3. 3.3 Temperature Measurement
      4. 3.4 OPP Definitions
    5. 4 Data and Results
      1. 4.1 OPP Settings and Linux Thermal Framework
      2. 4.2 Power and Thermal Chamber Measurements
      3. 4.3 OS Idle at OPP_NOM
      4. 4.4 Dhrystone 1 Core at OPP_NOM
      5. 4.5 Dhrystone 2 Core at OPP_NOM
      6. 4.6 Dhrystone 1 Core at OPP_HIGH
      7. 4.7 Dhrystone 2 Core at OPP_HIGH
    6. 5 References

3.4 OPP Definitions

Operating performance points (OPP) levels define a max frequency per fixed voltage level in each voltage domain. Table 1 lists the frequency of each subsystem per OPP for the AM574x processor.

Dynamic Voltage Frequency Scaling (DVFS) refers to a software technique where the system-on-chip (SoC) supplies with AVS support are changed from one OPP level (voltage and frequency pair) to another to either adapt to a changing work-load, or to avoid device operation outside of desired temperature bounds.

This SoC only supports DVFS on the MPU domain. For DSP and GPU domains, the OPP levels must be set during boot by the initial bootloader. Ensure that the selected OPP level meets the needs of the application and all thermal testing is conducted at the desired OPP level.

Table 1. Supported OPP vs Max Frequency

Voltage Domain Clock Domain OPP_NOM OPP_OD OPP_HIGH
Maximum Frequency (MHz) Maximum Frequency (MHz) Maximum Frequency (MHz)
VD_MPU MPU_CLK 1000 1176 1500
VD_DSP DSP_CLK 600 700 750
EVE_FCLK 535 650 650
VD_IVA IVA_GCLK 388.3 430 532
VD_GPU GPU_CLK 425.6 500 532
VD_CORE DDR3 / DDR3L 667 (DDR3-1333) N/A N/A
CORE_IPUx_CLK 212.8 N/A N/A
L3_CLK 266 N/A N/A
VD_RTC RTC_FCLK 0.034 N/A N/A